<!DOCTYPE html>
 <html lang="en">
    <head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initi
    al-scale=1.0">
 <title>特殊场景this绑定实验</title>
    </head>
    <body>
    <button>按钮</button>
    <script>
setTimeout(function() {
console.log("定时器函数:", this);
 }, 1000);

 var btnEl = document.querySelector("button");
 btnEl.onclick = function() {
 console.log("btn的点击（onclick）:", this); 17};
 btnEl.addEventListener("click", function() {
 console.log("btn的点击（addEventListener）:", this);});

 var names = ["abc", "cba", "nba"];
 names.forEach(function(item) {
 console.log("forEach:", this);
 }, "aaaa");
   </script>
</body>
</html>